Organizations and consumers increasingly use third-party services to store data. Third-party storage services may provide a number of benefits to customers, including flexibility, low capitalization requirements, add-on services, data sharing, and centralized access to data.
Many third-party storage customers want or need their data to be stored in an encrypted state due to privacy concerns or in order to ensure compliance with internal or external data-protection requirements, such as governmental laws and regulations, partnership agreements with other organizations, etc. As such, many traditional third-party storage services store customer data in an encrypted state.
While some conventional third-party storage services may create search indexes (e.g., keyword indexes) that enable a customer to search encrypted documents to which the customer has access, the mechanisms used by such conventional services to maintain search indexes may present unwanted limitations. For example, if a third-party storage service creates a separate search index for each of its customers and customers are allowed to share files, the third-party storage service may create many search indexes that contain duplicate information. In addition, if search indexes are not properly secured, they may reveal all or a portion of the private data contained in the documents that they index to other customers, intruders, and/or administrators of the third-party storage service. Accordingly, the instant disclosure identifies and addresses a need for additional and improved systems and methods for searching shared encrypted files on third-party storage systems.